title: Promoter-upstream activator sequences are required for expression of the xylS gene and upper-pathway operon on the Pseudomonas TOL plasmid.
abstract: Stimulation of transcription from the Pseudomonas TOL plasmid xylS gene promoter (Ps) and the upper-pathway operon promoter (Pu) is dependent on the positive regulator protein XylR activated by an effector molecule such as 3-cholorotoluene, and on RpoN, an RNA polymerase sigma factor. Mutational analysis of the Ps and Pu promoters showed that upstream activator sequences located between -110 and -218bp upstream of the main transcription initiation point are required for regulated expression from these promoters. A search for homologous nucleotide sequences in the -110 to -218bp region in Pu and Ps revealed conserved sequences that may act as putative recognition sequences for the XylR protein. Ps and Pu exhibit another well-conserved region at around -50bp, which is homologous to corresponding sites in other RpoN-dependent promoters and may constitute a binding site for integration host factor (IHF).
authors.affiliation: C.S.I.C., Estación Experimental del Zaidin, Granada, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Holtel
authors.forename: M A
authors.initials: MA
authors.lastname: Abril
authors.forename: S
authors.initials: S
authors.lastname: Marques
authors.forename: K N
authors.initials: KN
authors.lastname: Timmis
authors.forename: J L
authors.initials: JL
authors.lastname: Ramos
mesh_terms: D001483:Base Sequence; D004252:DNA Mutational Analysis; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D009876:Operon; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014050:Toluene / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D014050:Toluene